Vepdegestrant (ARV-471/PF-07850327) + Palbociclib vs Letrozole + Palbociclib in ER(+)/HER2(-) Advanced Breast Cancer
← catalyst calendarNCT05909397 · readout in 133 d
Sponsored by Pfizer (industry) · PFE — their whole pipeline →. With Arvinas Estrogen Receptor, Inc..
Phase
Phase 3
Status
Active, not recruiting
Study type
Interventional
Design
Randomized · None · Treatment
Enrollment
59actual
Sites
29
Countries
Australia, Brazil, China +7
Every value on this page is a field the sponsor filed with ClinicalTrials.gov, reproduced. Dates are their own estimates, revised as a study runs, unless the registry marks them actual. sources →
Source: ClinicalTrials.gov, retrieved 2026-08-19
Dates
each axis at the precision it was filed, with the registry's own basis| Date | Filed | Basis | What it is |
|---|---|---|---|
| Start | 2023-08-09 | actual | When the study began enrolling |
| Primary completion | 2026-12-30 | estimated | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2026-12-30 | estimated | The whole study's end, after follow-up |
| First posted | 2023-06-18 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2026-02-10 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- Breast Cancer
Interventions
- Drug: Vepdegestrant (ARV-471/PF-07850327) — also filed as Vepdegestrant
- Combination product: Palbociclib — also filed as IBRANCE®
- Drug: Letrozole — also filed as FEMARA®
- Combination product: Palbociclib — also filed as IBRANCE®
Primary outcomes
what the primary-completion date above is the date OFStudy Lead-in (SLI): Incidence of Grade 4 neutropenia
measured From randomization date up to Cycle 4 (each cycle is 28 days).
SLI: Incidence of dose reduction
measured From randomization date up to Cycle 4 (each cycle is 28 days).
SLI: Incidence of drug discontinuation.
measured From randomization date up to Cycle 4 (each cycle is 28 days).
Phase 3: Progression-Free Survival
measured From randomization date, every 12 weeks, to date of first documentation of progression or death, up to approximately 4 years.
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